Fix cannabis nutrient burn by flushing the growing medium with plain, pH-balanced water until the runoff clears, then restarting nutrients at roughly half the previous strength. Remove leaves that are fully crisped, leave the rest alone, and watch new growth over the next 5 to 10 days. Scorched leaves will not turn green again, but clean new tips mean the plant has recovered.
What does nutrient burn look like on cannabis?
Nutrient burn appears first on the newest growth and leaf tips. Tips turn brown or copper, curl upward, and feel dry or brittle. Severe cases show clawed leaves, burned margins, and stalled growth.
In soil grows the symptom often shows up two to five days after a heavy feeding, because salts accumulate before the plant reacts.
How do you fix nutrient burn step by step?
- Stop feeding. Use plain water only for the next one or two waterings.
- Check pH. Soil cannabis prefers about 6.0 to 7.0, while coco and hydro run closer to 5.5 to 6.5.
- Flush the medium. Run two to three times the pot volume of pH-adjusted water through the root zone.
- Measure runoff EC or PPM. If the runoff reads high, keep flushing until it approaches your target feed strength.
- Resume at half strength. Restart with about 50 percent of the previous nutrient dose and increase in small steps.
- Trim dead tissue. Snip leaves that are more than half dead so they do not invite mold.
How long does cannabis take to recover from nutrient burn?
New growth usually looks normal within 5 to 10 days of the flush. Full canopy recovery can take two to three weeks when plants are in late flower. Vegetative plants bounce back faster than flowering plants.
Can you reverse burned cannabis leaves?
No. Tissue that has turned brown and crisp is dead and will not regain color. The goal is protecting new growth, not saving scorched leaves.
What is the difference between nutrient burn and a deficiency?
- Nutrient burn from too much fertilizer: brown crisp tips on new leaves, upward curl, very dark green color, white salt crust on the medium.
- Nutrient deficiency from too little: yellowing between veins, pale new growth, and spots that spread from older leaves first.
Flushing makes a deficiency worse, so confirm the cause before you act.
How do you prevent nutrient burn?
Feed at a consistent strength and raise the dose in small increments instead of large jumps. Use a calibrated EC or PPM meter, and water to runoff in containers to push excess salts out of the root zone. Slow-release organic amendments rarely burn unless they are overapplied.
When should you ask a pro?
Bring photos and your feed log to a licensed cannabis store or cultivation class if symptoms spread after a flush. Experienced growers can catch pH imbalance, root problems, or pests that mimic nutrient burn.